2nd & 3rd paragraph <--- link
Our main or “key” light is fitted with the same silver umbrella and placed at the side position as before. In addition to this we have used our second head, fitted with a translucent, or “shoot through” umbrella. This fill light is placed close to the camera position slightly higher than the subject. It is set to give one f-stop less light than the main light onto the model.
This can be easily set up using a flashmeter and by taking readings from each head individually. e.g. if the main light is giving a reading of f/11, the fill should give a reading of f/8. Don’t forget to take another exposure reading with both lights and set that as your aperture.
2nd paragraph <--- link
In the diagram below you can see that we have placed a flash head quite close to the camera position and we have fitted a shoot-through umbrella. The power of this head has been reduced so it gives a meter reading at the subjects face of one f-stop less than the main light on the right. This ensures that we do not have flat lighting on her face and will give a very pleasing result. In this example the reading from the main light was f/11 (this was set on the camera) and the fill light was f/8.
isnt f/8 got more light than f/11? i understand that "f/8 let in more light than f/11 in camera term" but why is f/8 less light than f/11? oya, i'm assuming everything is constant(iso, shutter speed, distance of flash etc) except for the f-stop in the above 2 links.
is the f-stop terminlogy different for camera and studio lighting?